2022-09-09 05:09:21

by Li Zhong

Subject: [PATCH v1] fs/ext4/xattr: check the return value of ext4_xattr_inode_dec_ref()

Check the return value of ext4_xattr_inode_dec_ref(), which could return
error code and need to be warned.

Signed-off-by: Li Zhong <[email protected]>
---
fs/ext4/xattr.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 533216e80fa2..76141ed12bc2 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1540,7 +1540,9 @@ static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,

err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
if (err) {
- ext4_xattr_inode_dec_ref(handle, ea_inode);
+ err = ext4_xattr_inode_dec_ref(handle, ea_inode);
+ if (err)
+ ext4_warning_inode(ea_inode, "cleanup dec ref error %d", err);
iput(ea_inode);
return err;
}
--
2.25.1

2022-09-10 10:05:34

by Ojaswin Mujoo

Subject: Re: [PATCH v1] fs/ext4/xattr: check the return value of ext4_xattr_inode_dec_ref()

On Thu, Sep 08, 2022 at 09:47:27PM -0700, Li Zhong wrote:
> Check the return value of ext4_xattr_inode_dec_ref(), which could return
> error code and need to be warned.
>
> Signed-off-by: Li Zhong <[email protected]>
> ---
> fs/ext4/xattr.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
> index 533216e80fa2..76141ed12bc2 100644
> --- a/fs/ext4/xattr.c
> +++ b/fs/ext4/xattr.c
> @@ -1540,7 +1540,9 @@ static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,
>
> err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
> if (err) {
> - ext4_xattr_inode_dec_ref(handle, ea_inode);
> + err = ext4_xattr_inode_dec_ref(handle, ea_inode);
Hey Li,

My only concern here is in case ext4_xattr_inode_dec_ref() fails, we
overwrite the err value and the actual err from ext4_xattr_inode_write()
is lost.

I feel the ext4_xattr_inode_write() error code would be more valuable
for the calling function hence that is the one we should propogate.
Maybe we can just print the warning without overwriting err?

Regards,
Ojaswin
> + if (err)
> + ext4_warning_inode(ea_inode, "cleanup dec ref error %d", err);
> iput(ea_inode);
> return err;
> }
> --
> 2.25.1
>

2022-09-17 00:31:59

by Li Zhong

Subject: Re: [PATCH v1] fs/ext4/xattr: check the return value of ext4_xattr_inode_dec_ref()

On Sat, Sep 10, 2022 at 2:55 AM Ojaswin Mujoo <[email protected]> wrote:
>
> On Thu, Sep 08, 2022 at 09:47:27PM -0700, Li Zhong wrote:
> > Check the return value of ext4_xattr_inode_dec_ref(), which could return
> > error code and need to be warned.
> >
> > Signed-off-by: Li Zhong <[email protected]>
> > ---
> > fs/ext4/xattr.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
> > index 533216e80fa2..76141ed12bc2 100644
> > --- a/fs/ext4/xattr.c
> > +++ b/fs/ext4/xattr.c
> > @@ -1540,7 +1540,9 @@ static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,
> >
> > err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
> > if (err) {
> > - ext4_xattr_inode_dec_ref(handle, ea_inode);
> > + err = ext4_xattr_inode_dec_ref(handle, ea_inode);
> Hey Li,
>
> My only concern here is in case ext4_xattr_inode_dec_ref() fails, we
> overwrite the err value and the actual err from ext4_xattr_inode_write()
> is lost.
>
> I feel the ext4_xattr_inode_write() error code would be more valuable
> for the calling function hence that is the one we should propogate.
> Maybe we can just print the warning without overwriting err?
>
Thanks for pointing this out! I'll fix it in v2 patch.
>
> Regards,
> Ojaswin
> > + if (err)
> > + ext4_warning_inode(ea_inode, "cleanup dec ref error %d", err);
> > iput(ea_inode);
> > return err;
> > }
> > --
> > 2.25.1
> >